Integral wheel and drum



Feb. 4, 1958 M. G. WHITFIELD INTEGRAL WHEEL AND DRUM Filed July 6, 1953 INVENTOR INTEGRAL WHEEL AND DRUM Marshall G. Whitfield, Garden City, N. Y. Application July 6, 1953, Serial No. 366,281 Claims. (Cl. 301-6) This invention relates to vehicle wheels and more particularly to an automotive or aircraft wheel which is capable of carrying large torque loads and of quickly dissipating large amounts of heat.

Conventional aircraft or automotive wheels are usually constructed of aluminum or magnesium or strong alloys of these metals, such wheels are provided with frictional engaging surfaces for contacting a brake shoe. The frictional engaging surfaces are usually in the form of an iron or steel drum secured by bolts or rivets to the wheel. Under normal conditions such assembly of iron or steel drums and aluminum wheels have handled the normal dissipation of energy in the form of heat. However, such wheel assemblies when subjected to heavy loads, such as are encountered in aircraft using high speed take-01f and landing conditions, the heavy drums and brakes are unduly cumbersome and often inadequate. During the life of a brake on an aircraft it may never be called upon to absorb high energies of a rejected-take-ofi or emergency landing, consequently the aircraft is penalized by the excess weight of the brake, braking unit, fluid chambers, brake valves, etc. Present day truck and bus manufacturers are also seeking a stronger and lighter brake wheel assembly.

It is an object of the present invention to provide a strong and light-weight vehicle wheel composed of aluminum, magnesium or a strong alloy of either said wheel having a thin ferrous metal brake liner integrally bonded thereto by either a complex molybdenum-iron-aluminum alloy or by a complex tin-iron-aluminum alloy.

Another object of this invention is to provide an aluminum automotive or aircraft wheel having a steel or cast iron braking liner integrally bonded with the aluminum wheel with the afore-mentioned complex alloy and in particular an aircraft wheel which is capable of repeatedly withstanding the heat and torque developed in rejected-take-ofi or emergency landing conditions.

Still another object of this invention is to provide an aluminum or aluminum alloy aircraft wheel having a main body portion provided with an outer rim extending at right-angles thereto and adapted to engage the rim of a rubber tire, and an inner steel or cast iron liner integrally bonded with underside of the rim by a complex tin-iron-aluminum alloy or a complex molybdenum-ironaluminum alloy.

Yet another object of the invention is to provide an aircraft wheel composed of aluminum or aluminum alloy and a ferrous metal liner provided with ribs or similar extended surfaces which are intimately bonded with the aluminum or aluminum alloy rim portion by the aforementioned complex tin-iron-aluminum or complex molybdenum-iron-aluminum alloy.

Another object of the invention is to provide an aluminum or light metal vehicle or aircraft wheel having a segmented steel or cast iron liner integrally bonded by either of the afore-mentioned complex alloys to the underside of the rim portion of the wheel.

The above and other objects of the invention will be apparent upon reference to the following detailed description of my invention as shown in the accompanying drawings, in which:

Fig. 1 is a side sectional view of an automotive or aircraft wheel embodying the principles of my invention;

Fig. 2 is a partial sectional view of a modification of the wheel structure shown in Fig. 1, and;

Fig. 3 is a partial sectional view of a further modification of the wheel structure shown in Fig. 1 employing a segmented braking liner.

With reference to the drawings, Fig. 1 shows an aluminum or aluminum alloy wheel W cast in one piece having a main body portion 11 and a rim portion 12. A steel or cast iron brake drum 10 is integrally bonded by a complex aluminum-iron-molybdenum alloy or by a complex aluminum-iron-tin alloy 14 to the underside of rim 12 of wheel W. These complex alloy bonds retain their strengths at elevated temperatures up to substantially the fusion temperature of iron. There is no substantial measurable temperature gradient across the bonding alloy and heat generated in the ferrous liner is rapidly dissipated into the main body portion 11 of the aluminum wheel W. Despite the inherent difference in the coefficients of expansion, separation of the liner from the Wheel is prevented by the great strength of the complex intermetallic bond. As shown in Fig. 1 the main body portion 11 is provided with a curved outer surface 16 so as to approximate a streamlined effect. The inner surface 18 of the main body portion extends in a generally curved manner from the inside edge of the ferrous metal liner 10 to one edge of hub 20 which may be of conventional design. The annular ferrous metal liner 10 is thus conveniently located directly below the tire supporting rim 12 and absorbs torque directly from the tire. Due to the thinness of the steel or iron liner 10 it acts as an elastic part of the wheel and under heavy braking loads the ferrous liner may run somewhat out-of-round without serious effect.

Fig. 2 shows a partial sectional view of a modification of my invention in which the ferrous metal liner 24 is provided with a series of thin ferrous metal fins 26 pro jecting circumferentially out into the aluminum or aluminum alloy rim portion 28 of the aluminum wheel. These fins 26 assist in distributing both the torque and heat into the rim 28 and main body portion 30 of the wheel. Thin ferrous liners having fins or ridges of this nature have permitted rapid stops to be made without raising the temperature of the wheel above 500 degrees F. thus providing for a low rate of liner wear and preventing incipient fusion of the surface of the liner as is common in the use of an all-iron or centrifuge type of drum.

Fig. 3 shows a partial sectional view of a further modification of my invention in which the ferrous metal brake liner is formed of a plurality of segmented sections 32 each of which is bonded to the aluminum rim 34 by the hereinbefore mentioned complex alloy 36 of aluminumiron-molybdenum or aluminum-iron-tin. If desired, each segment may be provided with fins 38 to assist in distributing torque and heat to the body 40 of the wheel. The segmented liner construction, particularly with three or more segments will permit considerable out-of-round deformation to occur without serious damage to the wheel.

Tests have shown that when the fins extend approximately of an inch out from the liner into the aluminum, the structure remains intact after repeated conditions of great heat release.

For instance, a ferrous liner 15 inches in diameter consisting of six segments 0.160 inch thick, with inch fins extending 3 inch from the outer surface of the liner andspaced 5- inchapart-when bonded with" amolybdenum-iron-aluminum bond to an aluminum wheel substantially of the construction shown in Fig. 3 successfully absorbecl 10 million-'foot-pounds' of ltiiieticfenergy over a=period of 32- s'e'eonds withoutinjury.

uln condifions simulating a-rejeeted 't'ake o the castirun or steel liner may reach a temperature betweeri' 2W0 and 2200degrees' F L when measured- 0106 'mchfrom theffriction=- surfaces. "However; the integral-Wheel and'flfiicr assembly of the present invention" readily abfs'orbs and quickly dissipates this heafi withoutdeleterious efie'ct.

1 The integral! Wheel and" brake liner assembly of the present invention 'is obtained by "initially"depositing a layer or coating of either molybdenunr oi tinori the'exter nal surfaee-Ofi the casti'ron-"or steel-liner. Preferably molybdenum is -d'eposited by spraying* thedrum*with molybdenum. The -sprayed"drum is thenplacd ?in" a molten 'bath of aluminum and 'nece'ss'ai'y seemed 'to insure intimate-wetting of the ironbythealumitium. A

deposit of" 0.5 to 6 thousandths'of' aninchin tlii elhies'sis satisfactory. The molybdenum coateddrtmrwett'edwith aluminum is placed in af mold and molten aluminum" cast againstit'. The resulting complex bonding alloyf'bfdme molybdenum aluminum-iron" is sti'briglilid "hi'glll'y heatconductive. Tin is preferably electrolyticallfplated onto 'the drum toa thicknessbetweemTto S ThOu's'andths of 1 an 'inch. The plated drum may be-processed in "the same manner *as indicated *fbr -thed'r'um* heated" with molybdenummr itmay be' 'directly' casfwithoutithefdippingstep.

The complex aluminum-tinir'on bondor"the"complex aluminum*molybdenum-iron bond has" a remiie snengm and shearing strengthsuperior to the conventional aluminum-iron alloybonds used her'eto fo're: Por ins'tance',

aluminum 1 Wheels having-ferrous metal liners "ljfnided therein with the known iron-alum'inum"b'ond sl'rdweds'ei'i ous era'cksaft'era kinetic energy stop of 46"millidnif uot= pounds. Whereas similaraluminumWheels having-ferrous metal liners bonded therein with' a complex" ironmolybdenum alumi'num alley or thefiromalumihum-tin alloy didnot fail 'or show anycracks" after a "l ine'tic energy stop of 10 million foot-pounds.

Alcoa 43, 122; 132, 1 42, 1 195,320," 33 5;? 356," Frontier or-stainle'ss steel. If--desired;* the wlieel and liner-may be 1 heat treated to im rove physical 'properties and to stress relievethe aluminum.

-what'isclaimed i's: I I 1. Ina vehicle wheel a circular light-metal "main' body portion, a Y light-metal flange portion ciirc'umferer'itially disposed about and integral withsaid circular main-body portion, a radially and outwardly extending edge oneit her' sideof and integral with the-'outer"portion' er" 'said fiange functioning to-give conflgurationarid streri'gth tdsaid ffi together solely by" an intermediate "allloy layer of 'said '2. In an aluminum vehicle wheel for a pneumatic tire, a radially extending solid main-body portion, an ofi-set circumferential flange portion integrally formed with said main-body portion, radially and outwardly extending edges on the outer portion of said flange defining a pneumatic tire-supporting rim, a circular ferrous metal brake liner on the inner portion -of-said flange and having the outer lateraledgethereof substantially in the same radial plane as an edge ofsaidfl'ange; said'liner and said flange being joined together solely by an intermediate alloy layer selected fromthe group consisting of molybdenumiron-aluniihiimfifid tina'ron-amminum to present a continuous unbroken metallic path tothe'fiow of heat generated in said liner to said flange and main-body portion of said wheel.

3. A light-weight metal vehicle wheel as claimed in claim 2, in which. the ferrous metal brake liner is compo'sed of a1 plurality of segments, ac of said, segmears ha ing at'le'astio'ne' radial'iineXteiiding'intd and bonded by 'saidiii't'iniedia'te' alloy to saidaluminum flange.

4. In a ehicle wheel comprising renewradiall extendingjalui'riinurn 'bo'cly portion; a"p eriphe r'al and axially extending aluminum flangephr'tidn integrally farmed v'v ith' 'saidbodyi portion, said flange" portion having radially an; outwardly'ex'tendihg edgepo'rtions defining' a"pi ieiiii1atic' tire supporting iimjaci rcular ferrous m'et'al br'alge ,Iin'er'dispbs'ed' in contact with the inner surface of'said'aiiially" iit'eridiiig' aluminuin flange portion andfijo'iried the'r'eto 's'o1elyby a' metallurgical head cansistirigof aheat-c6'riductive intermediate" alloy layerselected from the g'r'oiip consisting, of 'fmolybdnum-iron- 'aiid'jtin-ii'dif-aluiiiiiiurn; said iiitermediate" alloy layer ha ifig'ja'thiclc'nessbetween 2 andS thousandthslof an'i'nch, thereby presenting a" continuous iinb'rolien' metallic'path'to'tliflow'of frictional heatf'ro'm saidlinr to said flange=andcircular"bdtly "portion; said cirularfhz'idyporintermediate alloy layer and incipient fusion (in the free surface of'said liner.

5. In a vehicle wheel comprising. a circular aliirtiiniiin bodyportion' having" an" annular aluiiiinu'm tire-supporting flange integral therewith;the-im rovement comprisin a ferrous nietal br'ake ]in'er"di'sposed radially inward y-er the'in'ner surfaceof isaid flange and having a free surface adapted tocontacf a'lbrakeflshoefa heat-co'riduc'tiye intermediate alloy layer selected "ne r the group consisungfof ilef'rnces flid in" the'file' of this patent UNITED -"STATES- PATENTS 

